1. Field of the Invention
The present invention relates to azo dyes useful in the dyeing of natural and synthetic fibers; particularly, wool and aromatic polyester, nylon and acetate fibers. More particularly, the invention relates to azo dyes prepared from, as a coupling component, a 3-chloro-2-methylaniline derivative.
2. Description of the Prior Art
Monoazo dyes derived from, as a coupling component, N-carboxyalkyl- or N-carboalkoxyalkylanilines are widely disclosed as dyes for both natural and synthetic fibers.
Dickey et al, U.S. Pat. No. 2,470,094, discloses monoazo dyes of the formula ##STR2## wherein R is hydroxyalkyl, --CH.sub.2 CH.sub.2 COOCH.sub.3 or --CH(CH.sub.3)CH.sub.2 COOCH.sub.3 ; R.sub.1 is hydrogen or methyl and X is hydrogen, methyl, ethyl or halogen, as being useful in the dyeing of nylon and vinyl acetatevinyl chloride copolymers.
McNally et al, U.S. Pat. No. 2,373,700, discloses azo compounds of the general formula: ##STR3## wherein R is the residue of a diazotizable amine; R.sub.1 is a benzene or naphthalene nucleus optionally substituted with substituents including methoxy, hydroxy, halogen and alkyl; R.sub.2 is hydrogen, an aliphatic group, a cycloalkyl group, a furyl group, a phenyl nucleus or ##STR4## X is a short chain saturated aliphatic hydrocarbon and Y is an aliphatic group, furyl or phenyl. The compounds are stated to possess application for the coloration of organic derivatives of cellulose, silk and wool.
Dickey et al, U.S. Pat. No. 2,723,264, discloses that azo compounds of the general formula: ##STR5## wherein R is hydroxyalkyl having 2-3 carbon atoms; R.sub.1 is CH.sub.3, --CH.sub.2 CH.sub.3 or --CH.sub.2 CH.sub.2 OH; R.sub.2 is H or --CH.sub.3 ; X is H, Cl, Br or --CH.sub.3 and Y is --OCH.sub.3, --OCH.sub.2 CH.sub.3 or --OCH.sub.2 CH.sub.2 OH, are particularly useful for the coloration of cellulose acetate textile materials.
In Fishwick et al, U.S. Pat. No. 3,097,198, it is disclosed that textile materials comprising artificial fibers, for example, cellulose acetate rayon, cellulose triacetate and polyester fibers, may be dyed in orange to blue shades possessing good fastness to light, washing and dry heat treatments using water-insoluble azo dyes of the formula: ##STR6## where D is benzene, thiazole or benzothiazole which may be substituted with NO.sub.2, --CN, --SCN, --CF.sub.3, methylsulfonyl or chloro; R is lower alkyl, aralkyl group or ##STR7## with m and n being 1 or 2, and E is hydrogen, lower alkyl or chloro.
Kruckenberg, U.S. Pat. No. 3,406,165 similarly discloses monoazo dyes for the dyeing of artificial fibers of aromatic polyester, polyamide, cellulose ester and the like. The dyes are azo compounds of the formula: ##STR8## wherein A is one of the radicals ##STR9## and R.sub.1 is hydrogen, methoxy, ethoxy or chloro; R.sub.2 is C.sub.n H.sub.2n-1 ; R.sub.3 is hydrogen, --CH.sub.2 CH.sub.2 CN, --CH.sub.2 CH.sub.2 COOC.sub.n H.sub.2n+1 or C.sub.n H.sub.2n+1 with n being an integer of from 1 to 5, and Ac is unsubstituted lower aliphatic carbonyl of 2-3 carbon atoms, chloro substituted lower aliphatic carbonyl of 2-3 carbon atoms, cyano substituted lower aliphatic carbonyl of 2-3 carbon atoms, hydroxy substituted lower aliphatic carbonyl of 2-3 carbon atoms, methoxy carbonyl, amino carbonyl and methylamino carbonyl.
British Pat. No. 491,793 discloses azo dyes suitable for dyeing cellulose esters and ether and which are prepared by coupling diazotized aromatic amines free from sulfonic acid groups with N-arylamino carboxylic acids of the general formula: ##STR10##
Fishwick, U.S. Pat. No. 3,637,652 claims disperse monoazo dyes of the formula: ##STR11## wherein A and B are each independently hydrogen, nitro or halogen; Y and Y' are each independently lower alkylene radicals; R is lower alkyl; R.sub.1 is hydrogen and lower alkyl and Z is hydrogen, lower alkyl and lower alkoxyl.
Sumner et al, U.S. Pat. No. 3,961,881, discloses a process for coloring synthetic polyamide employing a disperse dye such as a monoazo dye containing at least one carboxylic acid group and in the presence of a tanning agent.
Notwithstanding the plethora of monoazo dyes such as these disclosed in the art to be useful for dyeing synthetic fibers, there is still a great demand for dyes which have better fastness properties, or build-up on synthetic fibers or provide more desirable and brighter shades, or which provide the optimum compromise among the desired factors.
It is an object of the present invention, therefore, to provide dyes of excellent dyeing and fastness properties and which produce bright, desirable shades.
This and other objects of the invention will become apparent from the following summary and description of preferred embodiments.